As shown in FIGS. 11-15, a conventional ratchet wrench 50 contains a driving head 51, a receiving cavity 52 defined in the driving head 51, a first groove 53 formed on a rear end of the receiving cavity 52 and communicating with the receiving cavity 52, a second groove 54 arranged on a rear end of the first groove 53 and communicating with the first groove 53, a first hole 55 and a second hole 56 defined in the second groove 54, a steel ball 57 fixed in the second hole 56. The receiving cavity 52 includes a driving member 60 received therein, and the driving member 60 has a toothed portion 61 arranged around an outer wall thereof. The first groove 53 has two opposite retaining blocks 70 mounted therein, and each retaining block 70 has a plurality of teeth 72 formed around a front end thereof so as to retain with the toothed portion 61 of the driving member 60. The each retaining block 70 has a post 71 extending upwardly from a top surface thereof, and between the two retaining blocks 70 is defined a resilient element 73. The second groove 54 has a directional control member 80 fixed therein, and the directional control member 80 has an actuation portion 81 mounted on a front end of a lower side thereof, a positioning shaft 82 disposed on a rear end thereof, and a limiting slot 83, wherein the positioning shaft 82 is inserted into the first hole 55 of the second groove 54 so as to form a rotating axis of the directional control member 80.
Thereby, when the directional control member 80 is rotated toward one of the two retaining blocks 70, it is fixed by the limiting slot 83 and the steel ball 57, and the actuation portion 81 hooks a post 71 of the one of the two retaining blocks 70 so that a plurality of teeth 72 of the one of the two retaining blocks 70 disengage from the toothed portion 61 of the driving member 60, and the resilient element 73 pushes another retaining block 70 to move forward so that the another retaining block 70 abuts against the driving member 60 further, thus changing an operational direction of the ratchet wrench 50.
However, such a conventional ratchet wrench 50 has the following defects:
1. The positioning structure is complicated to increase manufacture cost and time.
2. An operating space has to be kept on an overlap area of the first groove 53 and the second groove 54 as illustrated in FIG. 13, so a height of the retaining block 70 is decreased, thus lowering an engagement area of the each retaining block 70 and the plurality of teeth 72.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.